01
Payments
Apply each payment to the right invoice.
Read remittance evidence, check balances and approvals, and post the allocation to the correct invoice.

02
Respect approval requirements
03
Verify the posting and balance
Recorded browser workflow
Recorded cash-application workflow with checkable final state.
Build around your payments workflow.
Define what your agent needs to do, the tools it uses, and what a correct outcome looks like.